2930.90.43.20 - Compounds containing a phosphorus atom to which is bonded one methyl, ethyl, n-propyl or isopropyl group, but no other carbon atoms

This HTS classification covers organophosphorus compounds characterized by the presence of a phosphorus atom directly bonded to one methyl, ethyl, n-propyl, or isopropyl group, and crucially, no other carbon atoms. These compounds typically function as intermediates or active ingredients in various applications, particularly within the agricultural sector. The specific structural limitation regarding the single alkyl group and the absence of other carbon chains attached to the phosphorus atom is key to distinguishing these chemicals.

While this category exists within the broader classification of pesticides, it is specifically defined by the chemical structure of the organophosphorus compound itself, rather than solely by its end-use. It differs from sibling categories such as fonofos (2930.90.43.10), phorate (2930.90.43.15), and terbufos (2930.90.43.30), which are defined by specific chemical names and often represent established pesticide active ingredients with distinct structural configurations beyond the narrow definition of this code. This category serves to capture compounds that meet the precise structural requirements but may not be listed by a common ISO name or are used in a broader capacity than just as a primary pesticide active ingredient.

As this classification represents a leaf node within the HTS, there are no further subdivisions. Classification into this code is determined by a strict adherence to the defined chemical structure: the presence of a phosphorus atom bonded to one specified alkyl group (methyl, ethyl, n-propyl, or isopropyl) and the absence of any other carbon atoms directly attached to that phosphorus atom. This ensures precise identification and differentiation from other organophosphorus compounds or pesticides with more complex structures.